Spray dampening apparatus

ABSTRACT

For a dampening apparatus for a printing machine as disclosed in U.S. Pat. No. 3,759,175 there is provided the additional element of means adapted to cause temporary variation in the output of spray from the apparatus by temporary and controlled partial or complete interruption of the spray output from the rotor. These means may be mechanical (e.g. a solid obstructor driven into or out of the spray path) or may be a variable air blast to deflect the spray or may be electrostatic.

United States Patent [1 1 Alsop 1 *Dec. 16, 1975 SPRAY DAMPENING APPARATUS [75] Inventor: Arthur Graham Alsop, Bristol,

England [73] Assignee: Strachan & Henshaw Limited,

Bristol, England Notice? 'l'he portion of the term of this patent subsequent to Sept. 18, 1990, has been disclaimed.

22 Filed: Jan. 25, 1974 21 Appl. No.: 436,829

[30] Foreign Application Priority Data Feb. 1, 1973 United Kingdom 5148/73 [52] US. Cl. 101/148; 101/366 [51] Int. C1. B41F 7/30; B41F 7/32 [58] Field of Search 101/147, 148, 366

[56] References Cited UNITED STATES PATENTS 51,891 1/1866 Campbell 118/D1G. 16 136,066 2/1873 Johnson 261/92 1,488,356 3/1924 Linke 239/224 X 1,944,876 1/1934 Cutler 134/194 UX 2,108,984 2/1938 Grembecki 101/147 2,368,742 2/1945 Brend 1l8/DIG. 16 2,454,594 11/1948 Christensen 261/92 X 2,689,523 9/1954 Koch 101/147 2,787,955 4/1957 Brodie 101/35 2,791,174 5/1957 Koch 101/147 2,889,856 6/1959 Magnuson. 137/823 X 2,960,929 11/1960 Erzinger 101/147 2,995,084 8/1961 Mosegaard 101/147 2,995,084 8/1961 Mosegaard 101/147 3,094,065 6/1963 Roberts 101/148 3,500,846 3/1970 Wood 137/823 3,759,175 9/1973 Alsop 101/366 X FOREIGN PATENTS OR APPLICATIONS 869,382 5/1961 United Kingdom 101/147 100,858 5/1937 Austria 261/92 627,480 9/1961 Canada 239/220 1,026,252 3/1958 Germany 118/D1G. 16 348,973 11/1960 Switzerland 101/148 Primary Examiner-J. Reed Fisher Attorney, Agent, or Firm-Jones, Tullar & Cooper 57' ABSTRACT For a dampening apparatus for a printing machine as disclosed in US. Pat. No. 3,759,175 there is provided the additional element of means adapted to cause temporary variation in the output of spray from the apparatus by temporary and controlled partial or complete interruption of the spray output from the rotor. These means may be mechanical (e.g. a solid obstructor driven into or out of the spray path) or may be a variable air blast to deflect the spray or may be electrostatlc.

6 Claims, 6 Drawing Figures US. Patent Dec. 16,1975 Sheet10f3 3,926,115

US. Patent Dec. 16, 1975 Sheet 2 of3 3,926,115

U.S. Patent Dec. 16,1975 Sheet3of3 3,926,115

SPRAY DAMPENING APPARATUS FIELD OF THE INVENTION This invention relates to dampening apparatus for printing machines. It is concerned with a modification of the apparatus shown in my US. Pat. No. 3,759,175.

BACKGROUND OF THE INVENTION It has become apparent that it is sometimes desirable to have a capacity for temporarily adjusting or cutting off the output of spray, particularly in the context of printing machines. It is desirable to have a quick response-time when an adjustment is needed so that waste of paper through incorrect damping is minimised, and especially in the case of a sheet-fed machine it may be desirable to cut off the dampener for short periods e.g. when there is a misfeed, or when the plate is being inspected.

In the said patent adjustment shutters 43 are shown. These may obtrude into a spray 37 of dampening liquid projected by projections 18 on a rotor from above a weir 25 forming one horizontal edge of a trough 26 continually fed with dampening liquid through pipe 28 so that liquid continually spills over the weir edge and the projections 18 cut into it to emerge where it spills and project the spray in a directional manner. These shutters are for the purpose of controlling distribution of liquid along the length of the dampener they are not quickly or readily adjustable and are not adapted for the present purpose.

SUMMARY OF THE INVENTION In the present invention I provide, in an apparatus as claimed in any claim of the said patent the additional element of means adapted to cause temporary variation in the output of spray from the apparatus by temporary and controlled partial or complete interruption of the spray output from the rotor. These means may be mechanical (e. g. a solid obstructor driven into or out of the spray path) or may be a variable air blast to deflect the spray or may be electrostatic.

The solid obstructor may take the form of a shutter movable in straight-line movements into or out of the spray path, or a projecting web on a rotatable shaft which latter by rotation brings the web to a greater or lesser extent into the path of the spray.

Three particular forms of embodiment of the present invention are shown in the accompanying drawings wherein:

DESCRIPTION OF DRAWINGS FIG. 1 shows diagrammatically a printing machine incorporating a dampening apparatus,

FIG. 2 is a sectional view of one embodiment of the apparatus of the present invention on a line C-C, FIG.

FIGS. 3 and 4 are sectional views (some parts being omitted in FIG. 4) on the lines A-A, B-B, respectively of FIG. 1,

FIG. 5 shows in a section analogous to that of FIG. 3 a second embodiment of the invention and FIG. 6 shows in a section analogous to that of FIG. 3 a third embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS For orientation purposes, some parts shown in the drawings are given the reference numbers used in said patent (the disclosure of which is incorporated by this reference) but are not described again here. and FIG. 1 of the present drawings illustrates diagrammatically the positioning of this present apparatus 13', 14 in a printing machine, which is a web or sheet-fed machine. Although a perfecting offset press is shown, the apparatus may be used in other forms of printing machine.

In FIGS. 2, 3 and 4, a temporary spray adjustment or cut-off shutter 61 for spray produced by a rotor 15 as described in my said patent is guided on rollers on pillars 62 which are attached to the front wall 23 of the cover 63 of the apparatus 13'14'. The shutter 61 moves in an approximately vertical plane seen in transverse section (FIG. 3) but with a lateral displacement since the rollers are received in obliquely inclined elongate slots 64 (FIG. 2). The shutter 61 is biased to its raised position by a spring 65 anchored to the front wall 63, and is driven downwardly by a pressure cylinder 66 anchored pivotally to a top wall 67 of the apparatus by lugs 68 and to the shutter by a shackle 69. Stroke of the shutter 61 is such that in its raised position indicated at line R, FIGS. 2 and 3, its lower edge is clear of the spray 37 and in its lowered position indicated at line L its lower edge interrupts all, or nearly all, of the spray. The liquid of the spray caught by the shutter falls into the trough 40 from which it can drain.

The shutter can be operated by alternative means, e.g. solely electrically or by a purely mechanical drive.

In FIG. 5, a solid obstructor takes the form of a pro jecting angled web 71 on a rotatable shaft 72. When the shaft rotates (through the angle between the solid and dotted line positions 71) it moves from a position wherein the web 71 is clear of the spray 37 to one where the spray is Completely interrupted. The response-time of this arrangement is very small.

The shaft may be rotated electrically or by a fluid, manual or mechanical drive.

A preferred arrangement is however a hydraulic piston and cylinder analogous to 66 (FIG. 2) driving a crank arm on the shaft. Air under pressure may be switched into the cylinder from an air source 74 or the cylinder may be exhausted through outlet 75 upon movements of a solenoid-operated valve 76.

Control of this valve may be manual through a pushbutton 77 (i.e. the operator can then temporarily adjust or cut off at will) or automatic. For an example of the latter, it would be advantageous in a sheet-fed machine for detection of a mis-feed automatically to cause cutoff of the spray, and maintain the cut-off until normal feeding is resumed. In a web-fed machine web breakage or web loss would be detected. A detection unit (known per se) is indicated at 78 and is arranged to give a signal to actuate the solenoid of the valve 76. Also, of course, the control may be designed to cause only a predetermined degree of interruption of the spray 37.

In FIG. 6, an arrangement is shown where the spray is deflected so that some or all of it is caught within the trough 40. Within the front wall 23 of the cover 63 is arranged an air duct 81 fed by a pipe 82, from a source of air under pressure. A slot-like aperture 84 directs air as shown by the lines 85. When air is thus blown it tends to deflect the spray 37 to the position 37 where nearly all of it is caught on the inner front wall of the trough 40 or the shutters 43. This embodiment is more suitable for temporary completely cutting off the spray rather than adjusting its output: but by control of the air pressure and rate of feed of air adjustment also 3 could be provided for.

Air is fed into the inlet pipe 82 from a valve controlled manually or by mechanisms (e.g. a misfeed detection unit) in the printing machine.

Analogously, an electrostatic field could be used to deflect a spray and adjust the amount of it received by the roll 11, 12 even to the extent of cutting it off.

I claim:

1. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, a cover for said rotor, said cover having a vertical front wall, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught, wherein the said actuable means is a shutter, means positioning the shutter above the base of the drain trough whereby it is movable in planar movement into and out of the spray path to catch liquid of the spray, so that the said liquid when caught can fall to the base of the drain trough, said shutter being between the front wall of the cover and the rotor, said shutter having a planar portion extending parallel to the axis of rotation of the rotor, said positioning means being located on the cover, obliquely extending slots in the planar portion of the shutter engaged by the positioning means whereby the planar movements of the shutter have a vertical component into and out of the path of the spray and a lateral component parallel to the axis of the rotor, and a drive element for the shutter arranged to drive the shutter in directions generally parallel to the axis of the rotor.

2. The improvement as claimed in claim 1 wherein the drive element is a fluid-pressure piston and cylinder arrangement and the control elements include a solenoid operated valve for switching pressure medium to and from the piston and cylinder and a control for an electrical power supply to the solenoid.

3. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught wherein the said actuable means is a web on a shaft, the shaft positioned parallel to the axis of the rotor and above the base of the drain trough, and being rotatable to bring the web into and out of the spray path to catch liquid of the spray, so that said liquid when caught can fall to the base of the drain trough.

4. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught by a said lip of the orifice wherein the said actuable means comprise air blast means which in operable condition act to deflect the spray path onto a lip of the said orifice so that the spray is at least partly caught by the lip.

5. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll ofa dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, the improvement consisting of a quickresponse means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught by a said lip or the orifice wherein the control elements include a detec tion unit in the printing machine effective to actuate the actuable means only when a fault condition is detected in the machine.

6. The improvement as claimed in claim 5 wherein the control elements include also a manually operable element effective to actuate the actuable means. 

1. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, a cover for said rotor, said cover having a vertical front wall, the improvement consisting of a quickresponse means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught, wherein the said actuable means is a shutter, means positioning the shutter above the base of the drain trough whereby it is movable in planar movement into and out of the spray path to catch liquid of the spray, so that the said liquid when caught can fall to the base of the drain trough, said shutter being between the front wall of the cover and the rotor, said shutter having a planar portion extending parallel to the axis of rotation of the rotor, said positioning means being located on the cover, obliquely extending slots in the planar portion of the shutter engaged by the positioning means whereby the planar movements of the shutter have a vertical component into and out of the path of the spray and a lateral component parallel to the axis of the rotor, and a drive element for the shutter arranged to drive the shutter in directions generally parallel to the axis of the rotor.
 2. The improvement as claimed in claim 1 wherein the drive element is a fluid-pressure piston and cylinder arrangement and the control elements include a solenoid operated valve for switching pressure medium to and from the piston and cylinder and a control for an electrical power supply to the solenoid.
 3. In a daMpening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught wherein the said actuable means is a web on a shaft, the shaft positioned parallel to the axis of the rotor and above the base of the drain trough, and being rotatable to bring the web into and out of the spray path to catch liquid of the spray, so that said liquid when caught can fall to the base of the drain trough.
 4. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defIning the outlet orifice, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught by a said lip of the orifice wherein the said actuable means comprise air blast means which in operable condition act to deflect the spray path onto a lip of the said orifice so that the spray is at least partly caught by the lip.
 5. In a dampening apparatus for a printing machine, the dampening apparatus having a supply trough, the trough having upstanding walls, one of said walls having a horizontal upper edge lower than upper edges of other walls thereby providing a weir edge, means for feeding liquid in the trough so that the liquid can be maintained at a given level in the trough higher than the level of the weir edge and spill continuously over the weir edge, a tangentially rigid rotor with an axis of rotation parallel to the weir edge and approximately vertically above it, thin projections on the rotor and axially spaced from one another along said axis of rotation, the said projections extending radially from and being spaced from the weir edge and extending to above the level of the weir edge and below the level of the liquid in the trough, means for rotating said rotor for causing the projections to cut into the thickness of the liquid over the weir edge to emerge where it spills from the weir edge to project directionally a spray of liquid and means positioning the dampening apparatus and a roll of a dampening train of the printing machine such that the said roll receives liquid directionally sprayed by the rotor, a drain trough below a path of the spray projected from the weir, a front wall of the drain trough being parallel to and spaced from the said one of the walls of the supply trough providing the weir edge, and a base of the drain trough extending from the said front wall to the said one wall, an output orifice for the spray being above an upper edge of the front wall of the drain trough, lips defining the outlet orifice, the improvement consisting of a quick-response means for adjustment of spray output from the dampening apparatus to the dampening train comprising means in the dampening apparatus actuable for preventing at least partially egress of spray from the apparatus and control elements for actuating the said actuable means, the said actuable means actuable between a condition in which the spray passes out through the orifice and a condition in which it is at least partially caught by a said lip or the orifice wherein the control elements include a detection unit in the printing machine effective to actuate the actuable means only when a fault condition is detected in the machine.
 6. The improvement as claimed in claim 5 wherein the control elements include also a manually operable element effective to actuate the actuable means. 